The leader of the British National party, Nick Griffin, has been barred from speaking at Bath University amid fears the event would bring chaos to the campus.

Earlier this week the university had said that Monday's meeting, which Mr Griffin was due to address, would go ahead because of the institution's commitment to freedom of speech.

But as the scale of the opposition became clear yesterday the university backed down. In a statement published on its website it said many students had expressed fears for their safety if the BNP leader was allowed to appear. It added: "The university has now learned that a very large number of protesters intend to arrive on campus. This creates the likelihood of substantial public order problems and real possibility of disruption ... making it impractical for the university to allow the event to go ahead. In the light of all these considerations the university has decided to refuse permission for the event to take place."

Mr Griffin was invited to address the meeting by first-year politics student and BNP youth leader Danny Lake, who told the Guardian he wanted Mr Griffin to visit the university to explain the BNP's policies to lecturers and students.

However, others said the meeting was part of an wider campaign by the BNP, which failed to make a breakthrough in this month's local elections, to establish a foothold on university campuses.

Last night Mr Lake described the university's decision as "a knee-jerk reaction to threats made by the undemocratic left - namely the unions and Unite Against Fascism who care not a jot for people's right to hold opinions".

Earlier student leaders and union officials said the initial decision to allow Mr Griffin, who has a conviction for inciting racial hatred, to address the meeting was naive, describing the BNP as dangerous and divisive.

Bath students' union passed a motion at an emergency meeting condemning the BNP and criticising the university.

Earlier 11 union general secretaries wrote to the university's vice-chancellor, Glynis Breakwell, calling on her to reconsider her decision.

Last night Sally Hunt, joint general secretary of the University and College Union, welcomed the university's U-turn: "We feel this is the correct decision. Allowing the BNP to speak would have compromised the safety of staff and students and sent out a very worrying message about Bath University's commitment to diversity.

"The millions of staff and students who cherish academic freedom ... deplore the presence in an institution of learning of Nick Griffin."

Paul Jaggers, president of Bath Student Union, said the decision "sends a clear message that students do not want the BNP on university campuses".